This invention relates to weighing apparatus incorporating half-bridge or full-bridge load cells and more particularly to such a weighing apparatus that is more economical to manufacture and has a lower profile than prior weighing apparatus of the same general type.
Half-bridge load cells include a pair of strain gages connected in series. Typically, the gages are mounted on a beam or other counterforce so that one gage responds to tensile and the other to compressive strain. To maximize the electrical output of the strain gages, it is desirable to apply the load to such a load cell at a point between the longitudinally spaced gages. This requires the use of a spacer and a bracket to allow the load point to be placed over the gaged beam.
For example, there is disclosed in U.S. Pat. No. 4,261,429 to Lockery a weighing apparatus in which a flexure beam is formed integrally with a plate at each of the four corners of the plate. A pair of strain gages is mounted on each of the beams. The load point for each of the load cells so formed is moved between the strain gages by means of a vertical spacer connected to the free end of the beam and a bracket connected to the spacer and extending parallel to the beam. The use of the spacers and brackets produces, in addition to increased cost, a higher profile weighing apparatus.